This is my experience with a Dell Inspiron E1505 and a Western Digital WD5000LPCX hard-disk drive.
The computer has a SATA-I (1.5-Gb/s) interface; the WD5000LPCX is a SATA-III drive and defaults to 6 Gb/s. In its default configuration, the drive is not recognized by the computer. The drive has four jumper pins. According to the Western Digital Web site, jumpering pins 1 and 2 enables spread spectrum clocking. Maybe so. I found that with those pins jumpered, the drive is recognized by the computer, and everything works fine. I'm posting from that computer, with that drive installed, right now.